Australia: Santos GLNG Starts Tunnelling Work

Santos GLNG launched tunnelling works underneath the Narrows Crossing in Gladstone Harbour.

This is a significant milestone for the multi-billion-dollar project as the tunnel will encase the gas transmission pipeline used to link the mainland to Curtis Island.

Santos GLNG Pipeline Manager Greg Jones said the tunnel would allow connection of the 420km underground gas transmission pipeline with the LNG Plant.

“A team of 12 people worked for around six weeks to assemble a 100 metre-long and 277- tonne tunnel boring machine on-site which will be used by Thiess to excavate through rock and soil and install the concrete tunnel lining,” Mr Jones said.

“This is a complex process that will take around 12 months to complete and will involve the creation of an approximately 4.3 km tunnel with a 3.4 metre internal diameter, and then placement of pipe.”

Thiess Tunnelling General Manager Steve Wille said the expertise Thiess has developed on Australia’s major road and rail tunnelling projects is now being applied to benefit of the oil and gas industry.

“The Tunnel Boring Machine (TBM) is a precision tool and our highly skilled team will guide it with pin-point accuracy to its destination across The Narrows,” Mr Wille said.

“The TBM cuts and removes the soil and rock, then lines the tunnel with pre-cast concrete segments in a remarkably seamless operation.”

Mr Jones said once the tunnel had been constructed, Saipem Australia the main contractor constructing the pipeline would pull the pipe through the tunnel.

“The tunnel will be flooded with water once it has been completed, and then the pipeline strings will be joined together and pushed through the length of the tunnel,” Saipem Australia Project Director Giuseppe Tassinari said.

Mr Jones said the development of the transmission pipeline was progressing well as the project worked towards first exports of LNG in 2015.

“We have now buried 60 km of pipe in Arcadia Valley and along the pipeline route almost 170 km has been cleared and graded, and 120km of pipe has been welded,” Mr Jones said.

“Rehabilitation work has started in Arcadia Valley which involves reinstating topsoil, sowing grass seeds and establishing pasture back on disturbed areas.

“We are working along the pipeline route, and undertaking clearing, grading and stringing work in the Banana Shire area in anticipation of pipe burial in coming months. Clearing and grading work in the Central Highlands area has also commenced.”

The Santos GLNG Project is a joint venture between Santos and three of the world’s largest energy companies, PETRONAS, Total and KOGAS.

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LNG World News Staff, April 15, 2013; Image: Santos